Conventionally, a technology that detects a rotation of a camshaft being provided at an internal combustion engine has been used (for example, Patent document 1). According to the technology disclosed in Patent document 1, a fitting portion of a bracket is inserted into a cylinder head cover in a state where the bracket is positioned at an upper portion of the cylinder head cover, and is connected to a cam cap with a connection bolt. Moreover, a cam angle sensor detecting a rotation of a rotor of the camshaft is positioned so as to be inserted into the cylinder head cover, and a flange portion of the cam angle sensor is connected to the bracket.
According to the technology disclosed in Patent document 1, a position of the cam angle sensor is fixed relative to a cylinder head by a support of the cam angle sensor relative to the cam cap serving as a support portion of the camshaft via the bracket. As a result, even if the resin-made cylinder head cover is deformed by, for example, a thermal expansion, the relative positional relationship between the cam angle sensor and a rotor can be maintained optimally.